Filter holder for coffee machine of the espresso type

ABSTRACT

Filter-holder comprising a cup (3) receiving a coffee filter (10) and having a perforated bottom, a body (25) arranged under the filter, an infusion collecting chamber (41) opening into a channel (43) of which the outlet (45) communicates with at least one distribution funnel (32), and a foam-forming device. According to the invention, the channel (43) extends annularly about a bossing (39) provided on the body, and the foam-forming device has an elastic annular seal (48) arranged about the bossing, closing the outlet (45) of the channel (43) and deformable by expansion in order to form at least one infusion flowing passage (51). Application particularly to a filter-holder for domestic coffee machines.

FIELD OF THE INVENTION

This invention relates to a filter holder, which is intended to bemounted on an espresso coffee machine and which contains a pan, suitablefor receiving a filter, which is intended to contain a measure of groundcoffee, said pan having a perforated bottom, a body arranged in the panbelow the filter, which is provided with at least one distributionfunnel, the lower end of which extends through the bottom of the pan, aninfusion collection chamber formed between the bottom of the filter andthe upper surface of the body and opening into an output strainer forthe infusion, the mouth of which communicates with said funnel,permitting the infusion to run toward the pan, as well as a device forthe making of foam.

BACKGROUND OF THE INVENTION

In a known filter holder of this type, used in an espresso machine,bringing hot water to the ground coffee contained in the filter at apressure of 10 to 15 bars, the production of foam in the infusionleaving the filter is achieved by passing the infusion through anover-pressure valve installed on the upper face of the body, and makingthe mouth of the infusion output strainer communicate with thedistribution funnel. However, such an over-pressure valve is anexpensive component and its installation on the upper surface of thebody is difficult to achieve.

OBJECT OF THE INVENTION

The main purpose of the invention is to remedy these defects and toachieve a filter holder of the type described above, which is equippedin a simple and lower-cost manner with a device making it possible toproduce abundant, thick foam from the infusion.

SUMMARY OF THE INVENTION

According to the invention, the strainer extends in an annular formaround a boss formed in the upper surface of the body, and the devicefor the making of foam has an annular elastic gasket placed around theboss, so as to obstruct the outflow from the strainer, said gasket beingdeformable by expansion under the effect of the pressure present in thecollecting chamber in such a manner, so as to form at least one passage,which places said output in communication with the funnel, permittingthe flow of the infusion.

Thus, this annular gasket, which is deformable elastically by expansion,constitutes a simple means to make it possible to obtain, as a result ofits expansion, an air-infusion mix sufficiently large to create a thickfoam in the coffee obtained. Furthermore, this gasket is inexpensive andis perfectly adapted to manufacturing these filter holders on a largescale.

According to another advantageous characteristic of the invention, thebody includes two funnels, arranged symmetrically on each side of theboss, and the filter holder also contains an annular distributionchamber, concentric with the gasket, containing two orifices, whichdischarge respectively into the two funnels and which is provided withchambers surrounding, on the one hand, only the periphery of the gasket,so as to leave free the peripheral sectors of the gasket, which arediametrically opposed, which extend in a plane perpendicular to thatpassing through the upper ends of the two funnels and which are intendedto be deformed by expansion so as to form two passages opening into thedistribution chamber and allowing the infusion, which is distributedequally, to flow into the two funnels via said orifices.

Thus, during the preparation of two cups of coffee placed below the twofunnels, one obtains, as a result of the particular arrangement of thetwo passages for the infusion, with respect to the two funnels, the sameflow of coffee through the two funnels and, therefore, the same quantityof coffee in each of the two cups.

BRIEF DESCRIPTION OF THE DRAWING

The characteristics and advantages of the invention are shown primarilyin the description, which will follow as an non-limiting example,referring to the attached drawings in which:

FIG. 1 is a vertical section of an inventive filter holder showing thefilter holder before the addition of hot water;

FIG. 2 is a partial view from above of a body installed in the filterholder of FIG. 1;

FIG. 3 is a view analogous to FIG. 1 showing the filter holder duringthe addition of hot water; and

FIG. 4 is a view analogous to FIG. 2 for the filter holder of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

The filter holder 1, represented in FIGS. 1 and 3, is intended to beinstalled on an espresso-type coffee machine and includes a pan 3 with alateral prolongation 5, to which a handle is attached (not represented),which permits it to be handled and, on its outside circumference,protrusions 7, which are intended to connect bayonet-fashion with afastening device present on a percolation head (not represented) of atype, which is of itself known, intended for the flow of hot water underpressure.

In the pan 3, a filter 10 is arranged, which is intended to contain ameasure of ground coffee and which is formed, in the example of theembodiment illustrated in FIGS. 1 and 3, of a cage 12 with lateralcylindrical wall 14 solidly fixed to the side wall 16 of the pan 3 and,through a flat bottom 15, provided with perforations 17, the peripheryof which rests on an annular sealing gasket 19 applied against the sidewall 14 of the cage 12.

The perforated bottom 15 of the filter 10 is attached, preferably at itscenter, for example, by means of a screw 22, into a body 25 in the pan 3below the filter 10 and made up of a cylindrical base 27, the peripheraledge 29 of which is anchored in the sealing gasket 19 and extendsdownward into distribution funnels 32, with vertical axes respectivelyXX' and YY', the lower end 32a of which protrudes from the bottom 34 ofthe pan 3 and the upper end 32b of which opens through the upper surface35 of the base 27. On this upper surface 35 of the base 27, there is acylindrical boss 39 on the vertical axis ZZ', into which the bottom 15of the filter 10 is screwed. As shown in FIGS. 1 and 3, the two funnels32 are arranged symmetrically with respect to the axis ZZ' of the boss39.

The filter holder 1 also includes an annular infusion collecting chamber41, which is placed between the perforated bottom 15 of the filter 10and the upper surface 35 of the base 27, and which opens into a strainer43 so that the infusion exit, the mouth 45 of which communicates witheach of the two funnels 32, allows the infusion collected to flow out ofthe pan 3 into two coffee cups placed below.

According to the invention, the strainer 43 runs in a ring around theboss 39 and the filter holder 1 is equipped with a device for theproduction of foam, which consists of an annular elastic gasket 48placed around the boss 39, suitable for sealing the mouth 45 of thestrainer 43 (FIG. 1 ) and which is deformable by expansion under theeffect of the pressure of the water passing through the ground coffeeand running in the collection chamber 41 in such a manner, so as to format least one passage 51 (FIG. 3), which places said mouth 45 incommunication with the corresponding funnel 32, so as to allow theinfusion to flow.

The gasket 48 is preferably made of an elastomeric material such as, forexample, a silicone rubber.

As shown in FIGS. 1 and 3, in this sample embodiment, the filter holderalso includes an annular distribution chamber 53, which is machined inthe base 27 concentrically with the gasket 48, and which is separated inthe collection chamber 41 by a plate 55, placed between the bottom 15 ofthe filter 10 and the upper surface 35 of the base 27. This distributionchamber 53, which is better visible in FIGS. 2 and 4, has two orifices57, opening respectively into the two funnels 32, and is provided withtwo vertical walls 58 circling only a part of the periphery of thegasket 48 in such a manner, so as to leave free two peripheral sectors61 of said gasket, which are diametrically opposite each other and whichextend in a plane perpendicular to that passing through the upper ends32b of the two funnels 32. These two free sectors 61 of the gasket 48are destined to be deformed by expansion under the effect of thepressure prevalent in the collecting chamber 41 in such a manner, so asto form two passages 51 (FIG. 3), which open into the distributionchamber 53 and allow the flow of the infusion, which is distributedequally in the two funnels 32 via the orifices 57 (see FIG. 4), thusadvantageously assuring the same quantity of coffee in each of the twocups.

In this example, the mouth 45 of the strainer 43 opens onto a peripheralchannel 63 placed around the boss 39, sealed by the gasket 48 (see FIGS.1 and 2) and is intended, after the expansion of the two free sectors 61of the gasket 48, to communicate directly with the two passages 51,respectively (see FIG. 3).

In FIG. 1, the gasket 48 is mounted on a disk 65 placed around the boss39 by being applied to the upper surface 35 of the base 27, and isinterposed in support, before expansion, between the plate 55 and thedisk 65. When the two free sectors 61 of the gasket 48 expand, theydisengage from the plate 55, in order to form, below the gasket 48, thetwo passages 51 opening into the distribution chamber 53.

Thus, when the hot water under pressure (symbolized by the arrows F onFIG. 3) is fed to the ground coffee contained in the filter 10, theinfusion, collected in the collecting chamber 41, passes into thestrainer 43 and then into the channel 63, causing the two free sectors61 of the gasket 48 to expand (FIG. 4) in such a manner, so as to flowthrough the two passages 51, forming the foam upon contact with the air.The infusion thus enriched with foam is distributed thereafter in anequal manner in the distribution chamber 53 and flows then equallythrough the two guide funnels 32 via the two corresponding orifices 57(FIG. 4).

I claim:
 1. A filter holder, which is intended to be installed on anespresso coffee machine, includes a pan, adapted to receive a filter,which is intended to contain a measure of ground coffee, said filterhaving a perforated bottom, a body, placed in the pan below the filterand provided with at least one distribution funnel, the lower end ofwhich extends through the bottom of the pan, an annular chamber tocollect the infusion formed between the bottom of the filter and theupper surface of the body and opening into a strainer, through which theinfusion exits, wherein the strainer extends in an annular fashionaround a bossing created in the upper surface of the body, the mouth ofthe strainer communicating with said funnel, permitting the infusion toflow out of the pan, and a device for the production of foam having anelastic annular gasket placed around the bossing, which is suitable forblocking the mouth of the strainer and which is deformable by expansionunder the effect of the pressure prevalent in the collection chamber insuch a manner, so as to form at least one passage, which places saidmouth in communication with the funnel, permitting the flow of theinfusion.
 2. The filter holder of claim 1, wherein the body, includestwo distribution funnels, placed symmetrically on each side of thebossing, said filter holder also including a distribution chamber,concentric with the gasket, which has two orifices opening respectivelyinto the two funnels and which is provided with walls blocking off onlyone part of the periphery of the gasket in such a manner, so as to leavefree two peripheral sectors of said gasket, which are diametricallyopposed, which extend in a plane perpendicular to that passing throughthe upper ends of the two funnels and which are intended to be deformedby expansion, so as to form two passages, which open into thedistribution chamber and allow a flow of the infusion, which isdistributed in an equal manner into the two funnels via the twoorifices.
 3. The filter holder of claim 2, wherein the mouth of thestrainer opens into a peripheral channel placed around the bossing,sealed by the gasket and is intended, after expansion of the two freesections of said gasket, to communicate directly with the two passagesof the infusion, respectively.
 4. The filter holder of claim 2 whereinthe collecting chamber and the distribution chamber are separated fromeach other by a plate, which is placed between the bottom of the filterand the upper surface of the body.
 5. The filter holder of claim 4,wherein the gasket is installed on a disk arranged around the bossingand applied to the upper surface of the body, said gasket beinginterposed, before the expansion, in support between the plate and thedisk, and the two free sectors disengaging said disk during theexpansion of said sectors to form the two passages opening into thedistribution chamber.
 6. The filter holder of claim 1, wherein thegasket is made of an elastomeric material.
 7. The filter holder of claim6, wherein the gasket is made of silicone rubber.